A dual circuit refrigerant condenser may be preferable to reduce system cost when, for example, a single fan can be used to urge air through the condenser. One proposed configuration of a dual circuit condenser uses a shared manifold that has a separator within the manifold to establish to isolated volumes within the manifold and thereby maintain distinct circuits. However, it has been discovered that some separator configurations undesirable increase stress on refrigerant conveying tubes fluidicly coupled to the manifold when the temperature of refrigerant in one circuit is substantially different from the temperature of refrigerant in the other circuit.